Gordon Brown is now confirmed as Tony Blair's successor as Labour leader and prime minister - after his only challenger, left-wing MP John McDonnell, failed to get enough backers. There are six contenders to succeed John Prescott as deputy Labour leader. Here is a guide to the runners and riders:

GORDON BROWN

Now that the moment of truth is upon him, a great weight appears to have been lifted from Gordon Brown's shoulders.

He has coveted the top job for more than a decade now, since agreeing to give fellow moderniser Tony Blair a clear shot at the party leadership in 1994.

He has built up an enviable reputation as chancellor but his tendency to brood about his thwarted leadership ambitions is the stuff of Westminster legend, along with tales of feuding and mistrust between the Treasury and Number 10.

Mr Brown has been in more relaxed and expansive form of late, as he tries the prime ministerial role on for size on a series of foreign trips and in keynote speeches on security and his pet subject "Britishness".

He was always the strong favourite to replace Mr Blair and will take over unopposed after Mr McDonnell failed to get onto the national ballot.

SUPPORTERS: His leadership campaign is being led by Commons leader Jack Straw. He is backed by 313 Labour MPs. Most of the big trade unions.

Had been touring the country since last July drumming up support from trade unionists and grass roots Labour activists, but failed to get the signatures of enough Labour MPs to get on to the ballot.

Even his supporters recognised he faced an almost insurmountable challenge.

There was a strong feeling on the left that Labour needed a radical change of direction - and that it should at least have had the chance to vote for one.

Mr McDonnell and Mr Meacher had agreed to pool their support, and said it amounted to the necessary 45 MPs. But Mr McDonnell conceded defeat when the scale of Mr Brown's nominations made it mathematically impossible for him to gain enough.

SUPPORTERS: He had nominations from 29 MPs, needing 16 more.

ALAN JOHNSON

Briefly touted last year as a possible leadership contender, Alan Johnson has contented himself with a bid for the deputy's job.

An affable figure with a plausible television manner, his working-class origins - and background as a trade union leader - might win him points with Labour's grassroots.

But he is also dyed-in-the-wool Blairite, who built his ministerial reputation on steering one of the most controversial of Blair reforms, university top-up fees, through Parliament in the teeth of left-wing opposition. Described by one minister recently as a "real player" in the government.

Says he wants Labour to narrow the class divide and has pledged to focus the party's efforts on retaining key marginal seats at the next general election..

SUPPORTERS: Has backing of 73 MPs. Possible support from CWU and Unison trade unions.

PETER HAIN

A smooth operator, who has displayed the odd flash of old-time socialism during his rise through the ministerial ranks.

An MP since Labour's most radical days in 1983, she has shown resilience by battling her way back towards the top, having been sacked as social security secretary in Tony Blair's first reshuffle in 1998.

Although a fierce Labour loyalist, she has never been afraid to speak her mind, recently ruffling colleagues' feathers with a call to make all of the attorney general's legal advice public.

Has also broken ranks since launching her deputy leadership bid to criticise the wealth gap and bash City bonuses.

Husband Jack Dromey is deputy general secretary of the TGWU union and Labour treasurer, who was famously kept in the dark on Labour's secret loans ahead of the 2005 election.

He says he was persuaded to run for the deputy leadership after pressure from delegates at Labour's conference in Manchester.

Although a former deputy political secretary to Tony Blair during his first term in office, he has more recently turned into a critic - unafraid to oppose the government on the imposition of university tuition fees.

He says the deputy leader should be a voice of the party to government and be distanced from the role of deputy prime ministership. Has trade union support and seems confident of gaining enough backing from MPs to get on to the ballot.

Has not been shy of criticising his more well-known rivals, dubbing Cabinet members "nodding dogs" posing as radicals in one recent interview.

SUPPORTERS: Has the backing of 49 MPs. Trade unions TGWU and Amicus.

HILARY BENN

Hilary "I'm a Benn not a Bennite" Benn has had a pretty swift rise up the ladder after his election in the Leeds Central by-election in 1999.

The son of left-wing icon Tony Benn, he is far more of a New Labour politician than his father but has a long career in politics behind him.

He served for 20 years as a councillor in Ealing, and was special adviser to the then Education Secretary David Blunkett after 1997.

After weeks of speculation, Mr Benn confirmed in late October last year he wanted to stand for the Labour deputy leader position - one his father missed out on by a whisker two and a half decades earlier.

A former local authority solicitor - and one of the original 1997 intake of "Blair babes" - she has served at the department of health, the Treasury and the Home Office, where she was in charge of counter-terrorism.

Has been a persistent and combative defender of controversial Blair policies on everything from tuition fees to the Iraq war.

But recently broke ranks to protest against hospital cuts and comment on the damage she believes is being done to the party by the "cash-for-honours" affair.

SUPPORTERS:Ms Blears has 49 nominations, including Home Secretary John Reid, Pensions Secretary John Hutton and ex-ministers Stephen Byers and Alan Milburn.

MICHAEL MEACHER

Probably the most experienced former minister on Labour's benches, having served in the Wilson and Callaghan governments in the 1970s.

Problems at the Home Office have led to him being all but written off as a contender by many commentators.

He was the last of the Cabinet heavyweights to declare his hand - and when he did finally rule himself out it was accompanied by the news that he would quit the Cabinet when Mr Blair goes.

Clearly a career as Gordon Brown's deputy was not part of his, or the chancellor's, immediate plans.

A reformed drinker who cut his teeth in the hard-nosed world of Scottish Labour politics, Mr Reid has held a string of Cabinet jobs, from defence to health, developing a reputation as a tough operator.

Has ruled himself out of running and said he will resign as home secretary when Mr Blair goes.

DAVID MILIBAND

Spent years saying he had no plans to stand for either the leadership or the deputy leadership - and has heaped praise on Gordon Brown as an excellent prime minister-in-waiting.

But his carefully chosen words, never overtly ruling out deciding to stand, did not stop speculation he could be persuaded to stand as a Blairite candidate against the chancellor. A series of "visionary" articles he penned and a wide range of newspapers urging him on all added to the sense he might be a contender.

He is seen as one of the brightest of his generation of Labour MPs, is highly rated by Tony Blair, although whether this is a help or a hindrance in the current climate is debatable.

Was talked up by some commentators as a fresher, younger alternative to Brown, who would wrong foot a Tory party which has built its whole strategy around the Chancellor's succession. But he eventually categorically ruled out a challenge three weeks before Tony Blair's declaration that he is leaving Downing Street.

CHARLES CLARKE

An ardent Blairite - who was nevertheless furious with the prime minister for sacking him as home secretary last year - Charles Clarke only ruled out a leadership bid in the week before Mr Blair said he was going.